Light signal



May 29, 1934. I w. B. WELLS LIGHT SIGNAL 2 Sheets-Sheet l 0rigi nal Filed Oct. 6, 1932 1 I r I my w. m m m m W 4 Bw weyley BY y 93 w. B. WELLS 1,960,765

LIGHT SIGNAL Original Filed Oct. 6, 1932 2 Sheets-Sheet 2 8a Fl .5

y INVENTOR weyley B wall BY azzwma HIS ATTORNEY Patented May 29, 1934 UNITED STATES PATENT OFFICE LIGHT SIGNAL Wesley B. Wells, Wilkinsburg, Pa., assignor to The Union Switch & Signal Company, Swissvale, Pa., a corporation of Pennsylvania.

3 Claims.

My invention relates to light signals, that is, to signals comprising a lamp and an optical device for projecting a beam of light from the lamp. One feature of my invention is the pro- 5. vision, in signals of this character, of novel and improved means for supporting the lamp.

The present application is a division of my copending application Serial No. 636,488, filed October 6, 1932, for Light signals.

' I will describe one form of light signal embodying my invention, and will then point out the novel features thereof in claims.

In the accompanying drawings, Fig. 1 is a vertical longitudinal sectional View showing one form of light signal embodying my invention. Fig. 2 is a sectional view on the line II--II of Fig. 1 looking in the direction indicated by the arrows. Fig. 3 is a detail view of one ofthe arms which comprises the supporting bracket 8 for the lamp of 2 the signal shown in Figs. 1 and 2.

Similar reference characters refer to similar parts in each of the several views.

Referring first to Figs. 1 and 2, the light signal in the form here shown comprises the usual casing C provided in its front wall with a large aperture 1, and having its opposite sides closed by removable doors 2 which permit convenient access to the interior of the casing for inspection or repair of the signal.

Located within the casing C is a light projecting unit A comprising a reflector 10 and an electric lamp 6 having a filament 6 which is located at the focal point of the reflector 10. The reflector 10 may be of any suitable type, but, as

here shown, it is of the type known to the trade as a Spheritoric mirror, and comprises a body of transparent material, such as glass, having a specularly reflecting rear surface of symmetrical curvature and a refracting front surface of 49 toroidal form. In reflectors of the type described,

the focal point is located on the axis of the reflector within the outlines of the reflector, so that the reflector collects the light rays emitted by the lamp over a solid angle of approximately 180, and the parts are so proportioned that the reflected rays form a concentrated beam of substantially parallel rays, as indicated by the dash lines 15, thus providing a very efficient light projecting unit.

The reflector 10 is supported in the desired position within the casing C by means of a suitable frame 9 comprising a flat plate bent to form a horizontal portion 9 and a vertical portion 9 The horizontal portion 9 rests on bosses 11 formed on the bottom of the casing C, and is provided with a pair of holes 12 through which clamping screws 13 which are screwed into threaded holes in the bosses 11 pass, thus securing the frame 9 to the casing. The vertical portion 9 of the frame 9 is provided with a centrally located aperture 14 having substantially the same diameter as the inner diameter of the reflector 10 at its edge, and the reflector is clamped against the vertical portion of the frame 9, directly back of the hole 14, by means of a suitable annular clamping member 16 and suitable screws not shown in the drawings. A ring or layer 16 of felt or other suitable material is interposed between the clamping member and the reflector to insure that the reflector will not be damaged by the clamping member.

The lamp 6, as here shown, has a single contact bayonet type base, and is of the precision type. That is to say, the lamp 6 is of the type having its filament accurately located with respect to its base. The lamp 6 is mounted in the usual socket 7, which socket, in turn is supported in an adjustable supporting bracket 8 embodying my invention. This supporting bracket, in the form here shown, comprises two oppositely disposed arms each similar to the arm shown in Fig. 3 and each consisting of a fiat strip of relatively rigid electrical conducting material such as brass, bent adjacent one end to form a semi-circular socket receiving portion 8 and provided at the 35 other end with an integral lug 8 which extends at right angles to the side of the strip. Each arm is provided on both sides of the associated socket receiving portion with a hole 8, and the two arms are fastened together with their socket receiving portions 8 facing each other. The socket 7 is clamped between them within the socket receiving portions 8 by means of two bolts 17 which pass through the aligned holes 8. The lug 8 on each arm is formed with a relatively large round hole 18 which receives with a considerable amount of clearance a terminal post 19 mounted on an insulated terminal block 20. The two terminal blocks 20 are secured to the vertical portion 9 of the frame 9, at diagonally opposite sides of the aperture 14, by means of suitable bolts 24, which bolts also serve as part of the means for fastening the clamping member 16 to the frame 9. A large washer 21 is placed on each terminal post 19 on each side of the associated lug 8 and these washers are clamped together to secure the associated arm to the associated terminal post by means of a clamping nut 22 and a lock nut 23.

It will be seen that with the supporting bracket constructed in the manner just described, due to the large amount of clearance which is provided between the holes 18 in the bracket 8 and the associated terminal posts 19, by loosening the nuts 22 and 23, the position of the bracket 8 may be shifted either up or down or sidewise through a considerable distance, thus providing for vertical movements of the lamp socket as well as horizontal movements in directions normal to the axis of the reflector. It will also be seen that by loosening the bolts 17, the socket 7 may be moved rec;-

tilinearly along and parallel to the axis of the reflector, and it follows, therefore, that provision is made for adjusting the position of the lamp filament in all directions through a sufficient distance to permit the filament to be accurately located at the focal point of the reflector. This adjustment is usually made at the factory during the assembly of the signal, and since precision type lamps are used, after the proper adjustment has once been made, it need not be disturbed.

Electrical connection with the shell of the socket '7 is made through either one of the terminal posts 19 and the bracket 8, while electrical connection with the central contact member of the socket '7 is made by means of a wire 35 which is fastened at its free end to a terminal post 19 similar to the terminal post 19. The terminal post 19 is mounted on an insulated terminal block 20 which is secured to the frame 9 in the same manner as the terminal blocks 20 are secured to the frame 9. Positioned directly back of the aperture 1 is a screen structure D, the function of which is to intercept light rays which enter the signal from the outside and to prevent these rays from being projected forward by the signal to give a phantom indication. Located in front of the aperture 1 is a cover glass 29 which serves to spread the light beam to the desired extent in the horizontal plane, and to direct a portion of the beam downwardly for close-up indications. The screen structure D and cover glass 29 as well as the means for, mounting them in thecasing C, are described in detail in my copending application Serial No. 636,488, but are not described herein because they form no part of the inventioncovered by the present application.

A hood 33 of the usual construction is secured to the casing C above the cover glass to protect this glass from the direct rays of the sun.

fithough I have herein shown and described only one form of light signal embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

l. A lamp supporting bracket comprising two oppositely disposed arms each consisting of a fiat strip of relatively rigid material bent adjacent one end to form a semi-circular socket receiving portion and provided at the other end with a lug which extends substantially at right angles to the side of the strip and which is provided with a relatively large hole, each arm being further provided with two holes one located on each side of the socket receiving portion, and means for fastening said two arms together in the relative positions in which their socket receiving portions face each other, said means comprising? two bolts one extending through the hole on the one side of the socket receiving portion in each strip and the hole on the opposite side of the socket rec'eiving portion in the other strip.

2. A light signal comprising a frame having an aperture, an optical projecting device secured to said frame in axial alignment with said aperture, two terminal posts secured to said frame on the opposite sides of the frame from said optical projecting device and at diametrically opposite sides of said aperture, a lamp supporting bracket provided intermediate its ends with lamp socket receiving means and at its ends with lugs located in a plane which extends at right angles to the axis of said socket receiving means, said lugs each being provided with a hole which receives one of said terminal posts with sufficient clearance to permit a considerable amount of movement of said bracket in all directions in a plane which is perpendicular to the axis of said optical projecting device, nuts screwed onto said terminal posts for securing said lamp supporting bracket in an adjusted position, a lamp socket disposed in said lamp socket receiving means and movable in an axial direction within said lamp socket receiving means, and means for clamping said lamp socket in an adjusted position within said socket receiving means.

3. A light signal comprising a frame having an aperture, an optical projecting device secured to said frame in axial alignment with said aperture, two terminal posts secured to said frame on the opposite side of the frame from said optical projecting device and at diametrically opposite sides of said aperture, a lamp supporting bracket comprising'two oppositely disposed arms each consisting of a flat relatively rigid strip provided at one end with a semi-circular socket receiving portion and at the other end with an integral lug which extends at right angles to the side of the strip, said arms being secured together with their socket receiving portions facing each other by means of bolts located at oppositesides of the socket receiving portions and said lugs each being provided with a hole which receives one of said terminal posts with sufficient clearance to permit a considerable amount of movement of said bracket in all directions in a plane which is perpendicular to the axis of said optical projecting device, nuts screwed onto said terminal posts for securing said bracket in an adjusted position, and a socket clamped between said socket receiving portions in an adjusted position by means of said bolts and movable along and parallel to the axis of said optical projecting device. 4

' WESLEY B. WELLS. 

